1. Technical Field
The present invention relates to a head mounted display to be mounted on user's head.
2. Related Art
An existing head mounted display (hereinafter, referred to as “HMD”) includes a display for the left eye and a display for the right eye. Therefore, it is difficult to reduce the head mounted display in size. In JP-T-2001-522477, JP-A-2001-209004, and JP-T-2007-524856, HMDs which can project an image for the right and left eyes with one display are described. Any of the HMDs described in JP-T-2001-522477 and JP-A-2001-209004 display an image for the left eye (or right eye) on an upper half of one display and an image for the right eye (or left eye) on a lower half thereof. Accordingly, in order to ensure resolution, the number of dots in the vertical direction needs to be increased. That is to say, although the number of displays is reduced, reduction of the HMD in size can barely be achieved.
The HMD described in JP-T-2007-524856 is an HMD which projects the same image for the right and left eyes. The HMD described in JP-T-2007-524856 splits one image displayed on one display by one half mirror (splitting mirror) so as to project the image for the right and left eyes. Accordingly, reduction in size can be achieved at some degree without sacrificing the resolution.
However, in the HMD described in JP-T-2007-524856, light from the display is focused by a biconvex lens (display optical system 115) to reach the half mirror. Accordingly, it is necessary that the display and the half mirror be arranged so as to be sufficiently distanced from each other. That is to say, it is difficult to sufficiently reduce the HMD in size. Further, in order to employ the above configuration, the biconvex lens and the half mirror need to be arranged with high accuracy. Therefore, the HMD is not easily manufactured.